(674h) Bio-Adhesion Properties of the Attachment Cement from the Tick Species Dermacentor Marginatus

In medicine, tissue adhesives are important surgical tools, but currently available products have either weak cohesive bonding forces (e.g. fibrin-based glues) or harmful side effects of toxic components (e.g. cyanoacrylate-based glues) [1]. Therefore there is a clear need for a new glue which is both biocompatible and strongly bonding (adhesion and cohesion). Unlike many technical glues on the market, a clinical adhesive must, of course, be effective in wet conditions. When ticks of the family ixodidae (Arachnida) feed they release a secretion, the cement. When the tick pierces the host animal’s skin with its mouthparts the tick is anchored into the skin by both mechanical and adhesive means as the cement bonds the tick to the tissue of the host [2]. The tick can then feed on the host’s blood. Therefore, the cement is acting as an adhesive in humid and wet conditions and is suggested to be biocompatible. The cement material is clearly of significant interest for research into new medical glues.

It is clear that investigating and understanding the adhesive properties of the tick cement is important for the development of new biocompatible tissue glues. In our experiments cement is harvested from the feeding of ticks on cattle blood through a silicone membrane. Further to histological investigations of the material components of the cement, in this work we have focussed on characterising the adhesive properties of this biomaterial. Testing has included measurements of the adhesion to the silicone membrane via pull off tests using a new adhesion testing apparatus. We have also used the surface forces apparatus (SFA) to measure adhesion from the tick cement material between differently modified surfaces. These results are supplemented by complementary atomic force microscopy (AFM) measurements, which reveal viscoelasticity.

One of the heavily researched routes for bio-inspired gluing in aqueous environments is using mussels and barnacles and our adhesion values are compared to equivalent SFA experiments on mussel foot proteins, which indicate that the tick cement is indeed strongly adhesive.

[1] Bhagat V & Becker L. Biomacromol. 2017;18(10):3009-3039

[2] Suppan J et al. Biol Rev Camb Philos Soc. 2018; 93(2):1056-1076